Qt and lwip-1.4.1

Josef Söntgen jsoentgen at ...2...
Mon Sep 17 13:47:53 CEST 2012

Hello Ivan,

On 09/17/2012 12:05 PM, Ivan Loskutov wrote:
> *After upgrade lwip to version 1.4.1 I have an issue in qt-network. In my
> fork was implemented Ssl support in qt-network for using in web browsers.
> With new lwip https doesn’t work. Http works, but I think with issues too.

Tbh, I only tested HTTPS support in noux-pkg/lynx which works fine but I
will take a look at SSL support in QtNetwork.

> I tried to investigate this issue. I think it is related to non-blocking
> sockets, which implemented in the new version. All simple examples are
> working properly. Issues occur only in a Qt application. I found that
> qtapplication calls connect and the connection started in non-blocking
 > mode, connect return EINPROGRESS. After qt made call connect again,
 > in such case connect must return EAGAIN, but it doesn’thappen in lwip.
> It doesn’t affect for http connection, but ssl connection is dropped.
> Anyone already faced such issues?*

Unfortunatly lwip does not support these errno value. It always returns
EALREADY even if the connection was already established. So we changed
this to EISCONN - which works fine for arora, because there is no code
in lwip that handles the various steps of a non-blocking connect() in
the socket-api (e.g. EAGAIN). That means you will get EINPROGRESS while 
lwip is connecting and EISCONN when it connected succuessfully.

Regards, Josef

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